Review of Flows Driven by Natural Convection in Adiabatic Shafts.
Review of Flows Driven by Natural Convection in
Zukoski, E. E.
NIST GCR 95-679; 46 p. October 1995.
Sponsor:National Institute of Standards and Technology,
Available from: National Technical Information Service
Order number: PB96-147897
buoyant flow; heat transfer; high rise buildings; high
temperature gases; leakage; smoke; stack effect; natural
convection; turbulent mixing
Experimental and analytic studies of the motion of hot
gases through vertical shafts under the influence of
buoyancy forces, carried out from 1973 to 1976 at the
California Institute of Technology, are reviewed. Such
flows originate in and have a hazardous effect during
accidental fires in facilities that involve vertical
shafts. Two mechanisms are primarily responsible for
vertical motion of buoyant gas within a building: stack
effect and the turbulent mixing process. This review
focuses on the turbulent mixing process, where the
vertical dimension of spaces of interest is much larger
than the horizontal, i.e., relatively tall shafts.
Particular emphasis of the work reviewed is on the
transient development of the mixing process within the
shaft as hot buoyant gas (e.g., smoke) is introduced
into the lower part of a shaft, which is at some
initial, uniform, and relatively low temperature.